For Windows die-hards, I'm sure there's a way to use PowerShell and either third party .NET charting programs or simply commandeer Excel to output the charts. This could also be done through the older VBScript or even famous underground swiss-army knife of tools used in IIS called LogParser with the output of CHART. I came across this blog on the topic:
For Java, long ago my friend in Japan mentioned JFreeChart.
Some other impressive ones were:
- AmChart, which have interactive charts in Flash or Silverlight.
- Open Flash Chart.
- PHP/SWF Charts - http://www.maani.us/charts/index.php
- Fusion Charts (http://www.fusioncharts.com/free/) support for jQuery and Joomla
- flot (http://code.google.com/p/flot/) - pure jQuery (javascript client)